UPDATE 1 — UK Stocks — Factors to watch on September 24
(Adds news items, updates futures) Sept 24 (Reuters) — Britain's FTSE 100 index opened down 0.2% on Thursday. CAPRICORN ENERGY: Capricorn Energy forecast annual production above the mid-point of its 18,000 to 22,000 barrels of oil equivalent per day guidance range. VISTRY: Vistry lowered its annual profit expectations,